Fuel loading and human activity are clearly important factors in the risk of fire. However, weather conditions including drought, high winds and extreme temperatures are often a major influence on the number, size, and intensity of bushfires in southern Australia.

Observations by the Bureau of Meteorology show that since the 1970s, fire danger has been rising in many parts of the country.

The average temperature of the continent has risen by almost a degree since Federation, while rainfall in the south has fallen. The mix of warmer and drier weather is raising the risk of severe, extreme and catastrophic fire weather conditions in southeastern Australia.

The fire season itself is spreading further into spring and autumn, with fewer and fewer opportunities for authorities to conduct hazard-reduction burns.

Fire authorities added 2 new danger ratings – severe and catastrophic – after Black Saturday. “Off the scale” fire danger (above an index of 100 for Catastrophic) has become more common.

2013 was Australia’s hottest year on record, with many places smashing local records.

Recent work by climatologists at the University of Melbourne shows that there is a 1 in 100 chance that the recent very hot weather is due only to natural causes. In other words, scientists can now say with a high degree of certainty that carbon pollution has made the weather hotter than it would otherwise have been.

The latest unusually hot weather is made even more so given that the Southern Oscillation Index currently sits in a weak La Niña to neutral state—one normally associated with cooler conditions.

TRUE
The costs of bushfires and other weather-related disasters are mounting.

The Insurance Council of Australia suggests that, from 1966, the insured loss from bushfires alone has totalled $5.6 billion in today’s money.

Victoria’s ‘Black Saturday’ bushfires of February 2009 cost the community more than $4 billion, according to the subsequent Royal Commission. This doesn’t include health and social costs, and flow-on costs to business.

Global reinsurer, Munich Re, recently predicted that the cost of all extreme weather events in Australia is set to soar from $6.3 billion a year today to about $23 billion a year in 2050—as the frequency and intensity of severe events like bushfires rises, together with rising population.

Aside from the physical injury from heat, flames, and smoke, the mental and social tolls impose substantial additional costs on communities. The cost in the treatment and lost productivity associated with mental disorders is already estimated at nearly $8 billion annually.